1. Field of the Invention
The present invention relates to a photosensitive drum for electrophotography.
This application is based on Japanese Patent Application No. Hei 10-153707, the contents of which are incorporated herein by reference.
2. Description of the Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
FIGS. 6 and 6A show a conventional electrophotography recorder using a photosensitive component in which photosensitive layers 51b and 51c are formed on a metal (for example, aluminum) drum (tubular component) 81a. FIGS. 7 and 7A show another conventional photosensitive component with photosensitive layers 54b and 54c formed on tubular film 54a. The photosensitive component is supported by two or more rollers 55, the mechanical drum is expanded, and the drum is gripped using grooves on the drum.
To manufacture the photosensitive component using the metal drum, the photosensitive layer is formed directly onto the metal drum by deposition, sputtering, dip-coating, or spray coating. When the photosensitive layer is deteriorated and abraded, the entire drum must be exchanged. Alternatively, the photosensitive layer may be polished, or may be removed by a solvent, to recycle the drum.
When using the photosensitive component using the tubular film, the tubular film is supported by two or more rollers under an appropriate tension. Therefore, when the photosensitive layer is deteriorated or abraded, only the tubular film can be exchanged.
The conventional electrophotography recorder, however, requires particular mechanisms which support the photosensitive component under appropriate tension, and which prevent meandering of the rotating tubular film. Further, a complicated mechanism which enables exchange of the component is required.
There is a problem with the metal drum that it cannot be easily disposed of or recycled, which increases the costs.
Further, there is a problem with the tubular film that the complicated mechanisms are required to support, rotate, drive, and exchange the film, thus increasing the costs.
Japanese Unexamined Patent Application, First Publication No. Hei 08-069233, discloses a drum for electrostatic photography which includes a porous damper. The damper is pressed against the inner surface of the drum, but the pressure of the damper becomes irregular because the drum lacks a means for producing a uniform pressure on the drum.
Japanese Unexamined Patent Application, First Publication No. Sho 63-249158, discloses a drum accommodating an elastic material whose ends are pressed by flanges in the direction of the drum axis. However, the pressure of the elastic material onto the inner surface of the drum, in particular, around the middle of the drum, becomes low because the pressures is applied only at the ends.
Japanese Unexamined Patent Application, First Publication No. Hei 03-179454 discloses a drum with a rubber component accommodated therein. Gas is injected into the rubber component so that the rubber component is pressed against the inner surface of the drum, but the drum lacks appropriate stiffness and it may be distorted because it uses the gas.
Japanese Unexamined Utility Model Application, First Publication No. Hei 01-171473 discloses a photosensitive drum which includes an elastic component. The ends of the elastic component are pressed by flanges in the direction of the drum axis. However, the pressure of the elastic material onto the inner surface of the drum, in particular, around the middle of the drum, becomes low because the pressures is applied only at the ends.
Other conventional photosensitive drums or electrophotograpy devices are disclosed in Japanese Unexamined Utility Model Application, First Publication No. Sho 60-163468, Japanese Unexamined Utility Model Application, First Publication No. Sho 60-165969, Japanese Unexamined Patent Application, First Publication No. Hei 5-035125, Japanese Unexamined Patent Application, First Publication No. Sho 63-249159, Japanese Unexamined Patent Application, First Publication No. Sho 64-072190, Japanese Unexamined Patent Application, First Publication No. Hei 05-094123, Japanese Unexamined Patent Application, First Publication No. Sho 63-013913, Japanese Unexamined Patent Application, First Publication No. Hei 06-123309, Japanese Unexamined Patent Application, First Publication No. Hei 07-281556, and Japanese Unexamined Patent Application, First Publication No. Sho 63-153572. These references describes the drum with an elastic material inserted therein, but lack a means for regulating the appropriate pressure and stiffness throughout the drum.